Welcome to objc.io issue #2!

First of all, we would like to thank everyone for the overwhelming response to our first issue -- we couldn't have hoped for a better start.

In this second issue we are going to dive deep into the subject of concurrent programming. These days, we have multiple CPU cores at our disposal, even on mobile devices. If we get concurrency right, it can give our applications a big performance boost.

Unfortunately, concurrent programming inherently has many intricate problems and pitfalls, no matter how simple the API makes it seem. We hope that the articles in this issue will give you a deeper understanding of the subject and help you navigate around the many potential pitfalls.

For this issue we are very glad to have Peter Steinberger and Tobias Kräntzer as guest authors. Peter shares his experiences with regard to concurrent programming from his well known PSPDFKit library, and Tobias writes about testing asynchronous code.

If you have a topic in mind that you would like to contribute to objc.io in the future, please get it in touch with us.

Lastly, we have good news for all of you who asked for an RSS feed: you can now subscribe to objc.io at objc.io/feed.xml.

Happy reading!

Chris, Daniel, and Florian.